If it's a pup, it will be growing up with the rodents and probably be ok. I've known several people with Rat Terriers and Manchesters and a couple of them grew up with rabbits and ferrets and had no problems with the ones in the house. Outside, that was a different story. The manchester seemed to find mice everywhere and killed them and brought them to his owner. He slept with two ferrets and had a huge rat and the ferrets as bed mates for a while when he was a pup. The rat was quite old and died in his sleep a few months after they got the pup, so I don't know what he would have done to other rats, but other ferrets were irresistible to him.